For 13.8, create a spice deck using ideal elements and run a transient
simulation using the analog input specified in the problem, and the appropriate
bit-switch voltages from your hand calculations for 13.8. Make sure
that the comparator input and output are what they should be. What
is the minimum gain that you need in the opamp to have it work properly
for this application (hint: consider the magnitude of analog signal that
needs to be amplified to become a digital value).

Replace the ideal elements from the previous simulation with elements of
your own design. Make sure that you still have the right voltage
levels at the output of the comparator!